以太坊私有链下智能合约部署

上一篇文章实现了搭建私有链，以下进行智能合约的部署

一、 编写合约

简单的乘法例子：

pragma solidity ^0.4.2;
contract test {

   function multiply(uint a) returns(uint d) {
       return a * 7;
   }
}

二、 编译合约

推荐网站：here

得到：Interface 和 Bytecode 和 Web3 deploy

Bytecode: 6060604052341561000f57600080fd5b5b60ab8061001e6000396000f30060606040526000357c0100000000000000000000000000000000000000000000000000000000900463ffffffff168063c6888fa114603d575b600080fd5b3415604757600080fd5b605b60048080359060200190919050506071565b6040518082815260200191505060405180910390f35b60006007820290505b9190505600a165627a7a723058206f9974e7f2c8329cbc09530d06d001018bfeca369c7cd8f9d565298adbdd2a9c0029

Interface: [{"constant":false,"inputs":[{"name":"a","type":"uint256"}],"name":"multiply","outputs":[{"name":"d","type":"uint256"}],"payable":false,"stateMutability":"nonpayable","type":"function"}]

Web3 deploy:
var browser_ballot_sol_testContract = web3.eth.contract([{"constant":false,"inputs":[{"name":"a","type":"uint256"}],"name":"multiply","outputs":[{"name":"d","type":"uint256"}],"payable":false,"stateMutability":"nonpayable","type":"function"}]);
var browser_ballot_sol_test = browser_ballot_sol_testContract.new(
   {
     from: web3.eth.accounts[0], 
     data: '0x6060604052341561000f57600080fd5b5b60ab8061001e6000396000f30060606040526000357c0100000000000000000000000000000000000000000000000000000000900463ffffffff168063c6888fa114603d575b600080fd5b3415604757600080fd5b605b60048080359060200190919050506071565b6040518082815260200191505060405180910390f35b60006007820290505b9190505600a165627a7a723058206f9974e7f2c8329cbc09530d06d001018bfeca369c7cd8f9d565298adbdd2a9c0029', 
     gas: '4300000'
   }, function (e, contract){
    console.log(e, contract);
    if (typeof contract.address !== 'undefined') {
         console.log('Contract mined! address: ' + contract.address + ' transactionHash: ' + contract.transactionHash);
    }
 })

三、 部署合约

在部署合约前，我们要明确需要以下几项条件：

1. 一个有Ether的账户；
2. 该账户已解锁；
3. 编译合约得到的abi和code。

所以首先需要做以下工作：

//创建账户
personal.newAccount('密码')

//挖矿，获得ether
miner.start()
miner.stop()

//账户解锁
personal.unlockAccount("第一个账户地址", "密码")

第一步： 获取abi信息，即上述编译得到的interface

abi = [{"constant":false,"inputs":[{"name":"a","type":"uint256"}],"name":"multiply","outputs":[{"name":"d","type":"uint256"}],"payable":false,"stateMutability":"nonpayable","type":"function"}]

得到结果：

[{
    constant: false,
    inputs: [{
        name: "a",
        type: "uint256"
    }],
    name: "multiply",
    outputs: [{
        name: "d",
        type: "uint256"
    }],
    payable: false,
    stateMutability: "nonpayable",
    type: "function"
}]
> 

第二步：

multiplyContract = web3.eth.contract(abi)

得到结果：

{
  abi: [{
      constant: false,
      inputs: [{...}],
      name: "multiply",
      outputs: [{...}],
      payable: false,
      stateMutability: "nonpayable",
      type: "function"
  }],
  eth: {
    accounts: ["0xbe98c12f918275591c9a43ec3c7bc44cfca50d2f"],
    blockNumber: 7,
    coinbase: "0xbe98c12f918275591c9a43ec3c7bc44cfca50d2f",
    compile: {
      lll: function(),
      serpent: function(),
      solidity: function()
    },
    defaultAccount: undefined,
    defaultBlock: "latest",
    gasPrice: 18000000000,
    hashrate: 0,
    mining: false,
    pendingTransactions: [],
    protocolVersion: "0x3f",
    syncing: false,
    call: function(),
    ... (一堆function)
}

第三步： 复制 Web3 deploy 到命令行

multiply = multiplyContract.new(
   {
     from: web3.eth.accounts[0], 
     data: '0x6060604052341561000f57600080fd5b5b60ab8061001e6000396000f30060606040526000357c0100000000000000000000000000000000000000000000000000000000900463ffffffff168063c6888fa114603d575b600080fd5b3415604757600080fd5b605b60048080359060200190919050506071565b6040518082815260200191505060405180910390f35b60006007820290505b9190505600a165627a7a723058206f9974e7f2c8329cbc09530d06d001018bfeca369c7cd8f9d565298adbdd2a9c0029', 
     gas: '4300000'  //改为300000
   }, function (e, contract){
    console.log(e, contract);
    if (typeof contract.address !== 'undefined') {
         console.log('Contract mined! address: ' + contract.address + ' transactionHash: ' + contract.transactionHash);
    }
 })

得到结果

{
  abi: [{
      constant: false,
      inputs: [{...}],
      name: "multiply",
      outputs: [{...}],
      payable: false,
      stateMutability: "nonpayable",
      type: "function"
  }],
  address: undefined,
  transactionHash: "0x87400471a0e32edcfa9e1ca621d08a318e9abb85299d280deb8bc199e118427f"
}

==> 在这一步，可能你会得到一条错误信息：

invalid sender undefined

解决方法: 在genesis.json文件中，chainId 不能设置为0。 如果你完全按照github上给的官方配置文件，就会产生这个错误

==> 在这一步，可能你会得到一条错误信息：

Error: authentication needed: password or unlock undefined

解决方法：先解锁账户啦

personal.unlockAccount("第一个账户地址", "密码")

==> 在这一步，可能你还会遇到这个问题：

Error: exceeds block gas limit undefined
The contract code couldn't be stored, please check your gas amount. undefined

解决方法：把gas改为300000。直接从那个网站的Web3 deploy 复制可能是4300000，然后改成300000，就没问题了。

猜测原因：

eth.getBlock("pending").gasLimit
web3.eth.estimateGas({data: bytecode})

可以先输入这两条来预判一下范围，取中间值。

第四步：然后我们需要挖矿确认

miner.start()

等待一会，你会得到一条信息：
Contract mined! address: 0xdb385bc97ed9fbac62920102d5edc7c4bf993c79 transactionHash: 0x87400471a0e32edcfa9e1ca621d08a318e9abb85299d280deb8bc199e118427f
==> 就代表部署成功啦。

miner.stop()

四、合约交互

第一步：获取合约对象

MyContract = eth.contract(abi)

得到结果：

{
  abi: [{
      constant: false,
      inputs: [{...}],
      name: "multiply",
      outputs: [{...}],
      payable: false,
      stateMutability: "nonpayable",
      type: "function"
  }],
  eth: {
    accounts: ["0xd88ad6d115ed640b69f01e24ff1433f75d5c8f87"],
    blockNumber: 4,
    coinbase: "0xd88ad6d115ed640b69f01e24ff1433f75d5c8f87",
    compile: {
      lll: function(),
      serpent: function(),
      solidity: function()
    },
    defaultAccount: undefined,
    defaultBlock: "latest",
    gasPrice: 18000000000,
    hashrate: 612,
    mining: false,
    pendingTransactions: [],

    ...（一堆function）
}

第二步：实例化合约

myContract = MyContract.at(multiply.address)

得到结果：

{
  abi: [{
      constant: false,
      inputs: [{...}],
      name: "multiply",
      outputs: [{...}],
      payable: false,
      stateMutability: "nonpayable",
      type: "function"
  }],
  address: "0xdb385bc97ed9fbac62920102d5edc7c4bf993c79",
  transactionHash: null,
  allEvents: function(),
  multiply: function()
}

第三步：调用合约

myContract.multiply.call(5)

得到结果：

35

五、在电脑B调用该合约

确定两台电脑已成功连接。电脑B上新建账户，并解锁。

1. abi = [{constant:false,inputs:[{name:'a',type:'uint256'}],name:'multiply',outputs:[{name:'d',type:'uint256'}],type:'function'}]  //合约的abi
2. address = 0xdb385bc97ed9fbac62920102d5edc7c4bf993c79  // 合约地址
3. myContract = web3.eth.contract(abi).at(address)

==> 然后就可以调用使用了 myContract.multiply.call(5)
得到结果：35